You've heard about electronic books, but they sound costly and complicated. Don't you need to buy some sort of device that syncs with your PC? Too much trouble. Glassbook. wants to change that impression. With Glassbook Reader software, you can read electronic books without having to buy any hardware beyond the computer you already own. And Adobe Systems Inc. will integrate Glassbook Reader into the next version of Adobe Acrobat Reader, which is expected to ship this summer. Glassbook Reader runs on any Windows PC. It supports Adobe PDF, so publishers and authors can retain the design and layout of their books. You can download a basic version of the Reader from Glassbook's Web site, and create your personal digital library by buying and downloading books from the Web. You can get the Plus version in a beta form for free, but the final version, scheduled for release in March, will cost around £30. The Plus version adds a dictionary and text- and file-searching; it also gives you the ability to lend or give your e-books to others. You can choose from approximately 100 titles on Glassbook's site, or find books at Barnesandnoble.com. Many titles are free. Prices vary by publisher, but are generally comparable to the price of paperback novels.